Everything from 5" drivers to 6x9s have been used in the rear doors. The rear doors will need minor modifications to accept a 6 x 9, though.
The components and coaxs would be a good start to a nice system, especially if you are planning on adding a sub at some point. For a very nice and cheap set of components, check out
www.madisound.com and get the Vifas that are listed on the sale page. They compare very favorably with most 300-400.00 component sets.
If you aren't planning on a sub, you may want to try to squeeze the 6x9s in their for some bass.
[This message has been edited by dnewma04 (edited January 15, 2001).]